Recently purchasing a GDEMU I am having a lot fun finding out what we can do with this awesome contraption.
After coming across a post by Razor X on the forum Sega extreme. He thought us how to change the menu also giving us access to making our own GDEMU Menu layout.
Here is a Video on how to do it your self. Download links are below
Original Source post by RazorX
Update (3 more themes added AtomisWave, Yu susuki Works, Gdemu Smart )